1. Field of the Invention
The present invention relates to a liquid crystal display (LCD) device, and more particularly, to an LCD device capable of improving low-voltage operability and transmittance, and a method for fabricating the same.
2. Discussion of the Related Art
According to development of an information-oriented society, demand for a variety of display devices have been gradually increasing. Meeting such demand, recently, researches have been carried out on various flat panel display devices including a liquid crystal display (LCD), a plasma display panel (PDP), an electro luminescent display (ELD), a vacuum fluorescent display (VFD) and so forth. Some of those display devices are already widely used in various kinds of equipment.
The LCD is particularly widely used, replacing a cathode ray tube (CRT) as a mobile image displaying device, since having several advantages such as an excellent image quality, lightness, compactness, and low power consumption. Besides the mobile use, for example as a monitor of a laptop, the application field of the LCD is increasing and diversifying to monitors of a TV that receives and displays broadcasting signals and of a general computer.
In general, the LCD mainly includes a thin film transistor (TFT) array substrate, a color filter array substrate, and a liquid crystal layer interposed between the two substrates.
The TFT substrate includes pluralities of gate lines and data lines arranged on a substrate horizontally and vertically to thereby define a plurality of pixel regions, a TFT which is a switching device formed at crossing positions of the gate lines and the data lines, and pixel electrodes formed on the pixel regions.
The color filter substrate includes color filters embodying colors, and a black matrix defining the color filters and preventing reflection of external light.
Here, a passivation layer which protects the TFT transmits light at the pixel region. However, since the passivation layer absorbs or reflects light, the optical transmittance would be deteriorated. Also, when forming a electric field for a common electrode and the pixel electrode, the electric field is weakened due to the passivation layer. Accordingly, a higher driving voltage is required.
Furthermore, because the liquid crystal cannot be favorably operated on electrodes, the transmittance is greatly deteriorated on the electrodes.